Insulated electrical conductor



Nov. 28, 1939. H. A. WINKELMANN 2,181,632.

INSULATED ELECTRICAL CONDUCTOR Filed April 29f 1957 Fll- CONC/actoFabric Patented Nov. 28,- 1939 l i n UNITEDy STATES lPMEISIT AOFFICE2,181,632 l msULATED. ELEUrmcAL CONDUCTOR Herbert A. Winkelmann,Chicago, Ill., assignor to ,MarbonCorporatiom Chicago, Ill., acorporation of Delaware A Application April 29, 1937, Serial No. 139,737

7 Claims. (Cl. 174-421) This invention relates to insulated conductors,Fig. l illustrates an insulated electrical conand more particularly toexible insulated wire ductor of the invention in which the stabilized inwhich the insulation comprises a rubber hyrubber hydrochloride of theinvention is in direct drochloride composition. contact with themetallic conductor.

Manytypes of dielectric materials have been Fig. 2 illustrates aninsulated electrical con- 5 applied to conductors, by various methods.In ductor of the invention in which the stabilized some cases theinsulation material is tubed on rubber hydrOChlOrde iS @Dated 0n fabricCOVeI- to the bare Wire; in other cases it is tubed over ing rubberinsulation.

a core of other insulation material. In many in- For purposes ofillustration, thefollowing for- JU stances the insulation material isdissolved in mulae which have been found suitable for wire 4a volatilesolvent and applied to the wire by insulation are given:

spraying, brushing, or dipping. lo

Insulation compositions of diierent types may Rubber .hydrochlonde 100100 o Magnesium oxide l0 10 be applied to the same Wire, as for example,rub- Litharge lo 10 15 ber may be tubed over bare wire, a fabric ap- 15plied over the rubber, and anothermaterial such Various resins such aschlorinated diphenyls, as cellulose acetate, vinyl resin, or the likemay phenol-aldehydes, ester gum, rosin, polycumaimpregnate and coat thefabric. This type oi rones, alkyds modified with resin acids or esterinsulated conductor is particularly used for ignigum, may beincorporated with the rubber hytion cable and for other conductorscarrying drochloride to increase the adhesion of the com- 20 highvoltages. For such cables, and to a certain position. These areparticularly valuable when extent for all insulated conductors, it isvery imthe composition is applied directly to the bare portant that theinsulation material not only wire. have high'dielectrc strength, -goodexibility, Plasticizers such as dibutyl phthalate, triwater resistance,and oil resistance, 4but it should cresyl phosphate, methyl abietate,soft chlorinat- 25 be able to withstand ozone and ultra violet light eddiphenyls, soft polycumarones', may be added due to corona effect. toincrease the flexibility of the compositions;

Rubber hydrochlorides have high dielectric Likewise, waxes such asparaffin wax, Opal wax, strength, are tough and iiexible even withoutcarnauba wax, beeswax, may be used in small plasticization, and havehigh water and oil reproportions to increase water resistance. 30sistance. Their resistance to ozone and ultra 'Ihese additionalmaterials are not essential violet light is also far superior to manyother and ordinarily should be used in minor amounts. insulatingmaterials. Naturally the type and amount of these mate- I havefound,however, that stabilized rubber rials must be chosen in accordance withtheir hydrochlorides are far superior to unstabilized dielectricproperties, water, oil, and ozone resist- 35 rubber hydrochlorides asinsulators for wires, and ance. give particularly valuable results whenused as a Various types of rubber hydrochlorides may be protectivecoating on ignition wires. To a large used. The amorphous rubberhydrochloride obextent this superiority is due to the increased re`-tainable by reacting sheet rubber with liqueed 40 sistance `ofstabilized rubber hydrochloride to hydrogen chloride is a saturatedproduct of ap- 40 ozone and togultra violet light. proximately 29% to30% chlorine content, of Although all stabilized rubber hydrochloridesgreaterI solubility and lower flow point than the are more effectivethan unstabilized rubber hycrystalline saturated rubber hydrochlorides.It drochlorides, I have obtained the best results is more readilyplasticized, and has less resistwith rubber hydrochlorides stabilizedwith magance to oils. The stabilized amorphous rubber 45 nesium oxide,magnesium carbonate, barium oxhydrochloride, however, has as highresistance ides, calcium oxide, and litharge. to ozone and ultra violetlight, and as good di- 'Ihese stabilized rubber hydrochlorides may beelectric properties as the crystalline types. The applied by methodsused for applying other inrubber hydroc loride obtainable by reactingsolusulating materials. They maybe tubed on to the tions of rub r withhydrogen chloride may be 50` wire or may be dissolved in volatilesolvents and partially saturated or saturated. These are cryscoated onthe Wire. For ignition cables the statalline rubber hydrochlorides whichwhen stabilized rubber hydrochloride is coated over the bilized comparefavorably for electric uses to the outer fabric covering. n amorphousstabilized product. For high ow Tn tli. i"$520lllpanying4 drawing:point, and extremely high resistance to oils. 56'

n a v l Q from the point of oil resistance, and resistance to v ultraviolet light. Also, compounds of over 40% chlorine content are generallytoo brittle. ll prefer to use a substantially saturated rubberhydrochloride stabilized with basic alkali earth metal compounds andbasic lead compounds.

It is to be understood that the rubber hydrochlorides include vulcanizedrubber hydrochlorides. As an example of tubed insulation of `vulcanizedrubber hydrochloride, the following is given:

Example A compound whichv consisted of:

Parts by Weight High teriperature, insoluble type rubber hydro- KetononeB. Hexamethylene tetramine was prepared by the usual milling-operation.

This compound was forced through a tubing machine to form the insulationfor, for example #16 gauge copper wire. The insulated wire was coiled incircular pans and buried in soapstone in the manner usually employedwith Wire insulated with natural rubber. The pan containing thesoapstone and insulated wire was then heated in open steam at 300 F. forone hour. The resulting product resembled insulated wire prepared withnatural rubber. Where high elasticity and resilience is not required,the vulcanizing -ingradients may be eliminated and the longcure replacedby a quick. molding operation. When this is done, the amount ofplasticizer, which prefaierccc Strength, exibility, water and oilresistancef` ozone and ultra violet ray resistance comprising aconductor wire covered with a composition of an intimate mixture ofrubber hydrochloride and a basic stabilizer.

2. An electrical conductor of high dielectric strength, exibility, waterand oil resistance, ozone and ultra violet ray resistance comprising aconductor wire covered With a composition of an intimate mixture ofrubber hydrochloride and a stabilizer including a basic lead compound.

3. An electrical conductor of high dielectric strength, flexibility,water and oil resistance, ozone and ultra violet ray resistancecomprising a conductor Wire covered with a composition of Aan intimatemixture oi rubber hydrochloride and a minor proportion of litharge.

4. An electrical conductor of high dielectric strength, flexibility,Water and oil resistance, ozone and ultra violet ray resistancecomprising a conductor Wire covered with a composition of an intimatemixture of rubber hydrochloride and litharge, and a member of the classselected from the group consisting of chlorinated diphenyls,polycumarones, ester gum, rosin, alkyl resins and phenol-aldehyderesins.

5. An electrical conductor of high dielectric strength, flexibility,water and oil resistance, ozone and ultra violet ray resistancecomprising a conductor wire covered with a composition comprising rubberhydrochloride, litharge and a l 6. An electrical conductor of highdielectric strength, flexibility, Water and oil resistance, ozone andultra violet ray resistance comprising a conductor Wire covered with aninner layer of insulating material, a layer of fabric covering saidinner layer, and a covering of a Water resistant stabilized rubberhydrochloride composition including a lead compound as a stabilizer onsaid fabric. v

7. An electrical conductor of high dielectric strength, flexibility,water and I oil resistance, ozone and ultra violet ray resistancecomprising a conductor wire covered with a composition of a vulcanizedrubber hydrochloride including a basic substance as a stabilizer.

HERBERT A. WINKELMANN.

